PPC and X86: Portable printing of IEEE floatswip/T18431

GNU as and the AIX assembler support floating point literals.
SPARC seems to have support too but I cannot test on SPARC.
Curiously, `doubleToBytes` is also used in the LLVM backend.

To avoid endianness issues when cross-compiling float and double literals
are printed as C-style floating point values. The assembler then takes
care of memory layout and endianness.

3 files changed, 9 insertions, 27 deletions

diff --git a/compiler/GHC/CmmToAsm/PPC/Ppr.hs b/compiler/GHC/CmmToAsm/PPC/Ppr.hs
index bb8d412f52..eef37f0db7 100644
--- a/compiler/GHC/CmmToAsm/PPC/Ppr.hs
+++ b/compiler/GHC/CmmToAsm/PPC/Ppr.hs
@@ -238,9 +238,8 @@ pprImm (ImmInteger i) = integer i
 pprImm (ImmCLbl l)    = ppr l
 pprImm (ImmIndex l i) = ppr l <> char '+' <> int i
 pprImm (ImmLit s)     = s
-
-pprImm (ImmFloat _)  = text "naughty float immediate"
-pprImm (ImmDouble _) = text "naughty double immediate"
+pprImm (ImmFloat f)   = float $ fromRational f
+pprImm (ImmDouble d)  = double $ fromRational d
 
 pprImm (ImmConstantSum a b) = pprImm a <> char '+' <> pprImm b
 pprImm (ImmConstantDiff a b) = pprImm a <> char '-'
@@ -338,13 +337,8 @@ pprDataItem platform lit
                     <> int (fromIntegral (fromIntegral x :: Word32))]
 
 
-        ppr_item FF32 (CmmFloat r _)
-           = let bs = floatToBytes (fromRational r)
-             in  map (\b -> text "\t.byte\t" <> pprImm (ImmInt b)) bs
-
-        ppr_item FF64 (CmmFloat r _)
-           = let bs = doubleToBytes (fromRational r)
-             in  map (\b -> text "\t.byte\t" <> pprImm (ImmInt b)) bs
+        ppr_item FF32 _ = [text "\t.float\t" <> pprImm imm]
+        ppr_item FF64 _ = [text "\t.double\t" <> pprImm imm]
 
         ppr_item _ _
                 = panic "PPC.Ppr.pprDataItem: no match"
diff --git a/compiler/GHC/CmmToAsm/Ppr.hs b/compiler/GHC/CmmToAsm/Ppr.hs
index 405bab9fff..9c8a19cee7 100644
--- a/compiler/GHC/CmmToAsm/Ppr.hs
+++ b/compiler/GHC/CmmToAsm/Ppr.hs
@@ -9,8 +9,6 @@
 -----------------------------------------------------------------------------
 
 module GHC.CmmToAsm.Ppr (
-        castFloatToWord8Array,
-        castDoubleToWord8Array,
         floatToBytes,
         doubleToBytes,
         pprASCII,
@@ -43,8 +41,6 @@ import qualified Data.ByteString as BS
 import GHC.Exts
 import GHC.Word
 
-
-
 -- -----------------------------------------------------------------------------
 -- Converting floating-point literals to integrals for printing
 
@@ -92,6 +88,7 @@ doubleToBytes d
         return (map fromIntegral [i0,i1,i2,i3,i4,i5,i6,i7])
      )
 
+
 -- ---------------------------------------------------------------------------
 -- Printing ASCII strings.
 --
diff --git a/compiler/GHC/CmmToAsm/X86/Ppr.hs b/compiler/GHC/CmmToAsm/X86/Ppr.hs
index 49e4de8ad5..942e7a0858 100644
--- a/compiler/GHC/CmmToAsm/X86/Ppr.hs
+++ b/compiler/GHC/CmmToAsm/X86/Ppr.hs
@@ -426,9 +426,8 @@ pprImm (ImmInteger i) = integer i
 pprImm (ImmCLbl l)    = ppr l
 pprImm (ImmIndex l i) = ppr l <> char '+' <> int i
 pprImm (ImmLit s)     = s
-
-pprImm (ImmFloat _)  = text "naughty float immediate"
-pprImm (ImmDouble _) = text "naughty double immediate"
+pprImm (ImmFloat f)   = float $ fromRational f
+pprImm (ImmDouble d)  = double $ fromRational d
 
 pprImm (ImmConstantSum a b) = pprImm a <> char '+' <> pprImm b
 pprImm (ImmConstantDiff a b) = pprImm a <> char '-'
@@ -517,13 +516,8 @@ pprDataItem config lit
         ppr_item II16  _ = [text "\t.word\t" <> pprImm imm]
         ppr_item II32  _ = [text "\t.long\t" <> pprImm imm]
 
-        ppr_item FF32  (CmmFloat r _)
-           = let bs = floatToBytes (fromRational r)
-             in  map (\b -> text "\t.byte\t" <> pprImm (ImmInt b)) bs
-
-        ppr_item FF64 (CmmFloat r _)
-           = let bs = doubleToBytes (fromRational r)
-             in  map (\b -> text "\t.byte\t" <> pprImm (ImmInt b)) bs
+        ppr_item FF32 _ = [text "\t.float\t" <> pprImm imm]
+        ppr_item FF64 _ = [text "\t.double\t" <> pprImm imm]
 
         ppr_item II64 _
             = case platformOS platform of
@@ -561,9 +555,6 @@ pprDataItem config lit
                   _ ->
                       [text "\t.quad\t" <> pprImm imm]
 
-        ppr_item _ _
-                = panic "X86.Ppr.ppr_item: no match"
-
 
 asmComment :: SDoc -> SDoc
 asmComment c = whenPprDebug $ text "# " <> c